Harmonic characteristic of sample time staggered space vector modulation for multi-modular or multilevel converters

Sample time staggered SVM (STS-SVM) is a new modulation strategy for high power equipments, which has been successfully applied to multi-modular converters and cascade multilevel converters. Instanced by a kind of minimum switching loss SVM (MSL-SVM) in this paper, its modulation model is derived by dual Fourier transforms. The modulation model in frequency domain of STS-SVM is then deduced and the harmonic characteristic of that is analyzed quantitatively. The conclusions are drawn that this technique can largely improve the equivalent switching frequency with no fundamental component loss. This conclusion is the same with other kinds of SVM. Experimental results verified the theoretical analysis.